Operating mechanism for crossbar line switches



Aug. 21, .1923. r 1,465,361

A. c. MAG RATH OPERATING- MECHANISM FOR CROSSBAR LINE SWITCHES Filed Oct. 15, 1920 2-Shee A. C. MAGRATH OPERATING MECHANISM FOR CROSSBAR LINE SWITCHES Aug. 21, 1923. 1,465,361

ile 00V 15 1920 2 Sheets-Sheet 2 Patented Aug. 21, 1923.

UNITED STATES; v .;"r|z'1-11" OFFICE;

ARTHUR C. MAGRATH, F BROOKLYN, NEW YORK, ASSIGNOR, T0 WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK.

O PERATING MECHANISM FOR CROSSBAR LINE SWITCHES.

Application filed October 15,. 1926. "serial no.4i7,oes,

T 0 all whom it mdy concerni .Be it known that I, ARTHUR C. MAGRATH, a citizen of the United States, residing at Brooklyn, in the county of Kings, State of 5. New York, have invented certain new and useful Improvements in Operating lvlecha. nism for Crossbar Line Switches, of which the following. is a full, clear, concise, and exact description. v

This invention relates to line switches of the cross bartype such as are used automatictelephone exchanges for interconnecting subscribers line and trunk lines extendingto first selector switches. More articularly it relates to an operating mechanism for selectively moving the trunk bars of cross bar line switches into positions wherein they can be engaged for the establishment of connections, and for releasing 2o thetrunk bars after connections have been established therewith. I i g In evolving the present invention the object in view was the provision of a mechanism for the above stated purpose requiring a minimum of parts, particularly moving parts, which would be economical to manufacture and which would notbe likely to get out of order. v

Thepredominantffeature of the present invention is a unitary device which performs the, two functions above noted, namely, preselecting the trunk bars, that is, setting'them into their operative positions wherein they can be engaged by the line bars and releasing the trunk bars after they have been so engaged. l

In the co-pending application of J. N. Reynolds Serial No. 416,835, filed October 14, 1920, the mechanism of the present invention is described in connection with a complete cross bar line switch.

With reference to the accompanyingdraw ings; Fig. 1 is a fragmentary crossisectional view of a. cross bar line switch taken along the line 1-1 of Fig. 3; Fig. 2 is an end elevation of thetru'nk bar operating mechanism taken at the lefthand'end of Fig. 1 showing the trunk selecting commutator and the motor magnet for rotating the mechanism; Fig. 3 is a ores sectional view along the line 33 of Fig.1. 1

In the preferred embodiment of this invention the trunk bar operating mechanism is situated midway between two groups of trunk bars, that is :an upper and ailower should be in its preselected position at -any YORK, N. Y., aconronn'rron on NEW group. Each trunk barb is situated directlyove r a lower trunk bar'with Which, it is electricallyconnected and i with which it is simultaneously operated,

In Fig. 3 there is shown a lower end of an;

upper trunk bar andthe upper. end of a lower trunk bar, These are designated by the numeral 1. Between the two trunk bars there is shown the operating mechanism.

Ordinarily cross bar line switches areadapted to accommodate ten or twelve trunk lines. If a switch in accordance withthe present inventlon is intended to accommodate say twelve trunk lines then there would be pro. vided twelve trunk bars'inthe upper group and twelve in the lower group, or if the switch is intended to accommodate ten trunk lolnes each group would comprise ten trunk ars. Each trunk bar is pivotally mountedin the bearings 3, one at each end of thetiunk bar. The trunk bars are adapted to "rotate through a small angle about their pivots into their, preselected positions. In Fig. 1 four triink bars are shown in cross section all ofwhich are in their normal positions except the second one from the right hand side of the figure which is shown in its pre- 7 selected position. It will be noted that the preselected trunk bar has been displaced through a small angular distancejfrom its normal position. i v I The third trunk bar from the right in'Fig'.

1 is seen to be engaged by a line bar 2. This .ing quite flexible permit the trunk bar to return to normal while remaining in en- ,gagement with a live bar.

It-is essential that only one trunk bar onetime, and it is further essential that as soon as a preselected trunk bar jis engaged by a line bar it shall be returned'to its nor- I mal position and that asucceeding idle trunk bar shall be immediately-rotated into its preselected position to be ready for the next call. V. v. v

Each trunk bar isprovided with a lateral ly extending arm 4 by. means of which is rotated. A fiat spring 5 bears against each arm 4 and holds the trunk bar in its normal position when the latter is not displaced from normal by the operating mechanism and returns the trunk bar to normal when it is released from its preselected position.

A shaft 6 extending transversely of the trunk bars is journaled in bearings 7 and 8 and is rotatable, and movable longitudinally therein. A spring No. 9 tends to hold shaft 6 in its normal longitudinal position as shown in Fig. 1 and is effective to return the shaft to normal after it has been displaced longitudinally. Shaft 6 is rotatable by means of ratchet wheel 10, mounted thereon and engaged by pawl 11 which is carried by armature 12 of motor magnet 18.

Mounted on shaft 6 and situated at equal intervals are a plurality of disks 14, one for each pair of trunk bars, that is, upper and lower contiguous trunk bars. The disks are rotatable and longitudinally movable with shaft 6. Each disk is provided with two diametrically opposite lugs 15 and two diametrically opposite slots 16, the latter being at right angles to the lugs.

Lugs 15 are operable upon a longitudinal movement of shaft 6 to engage and rotate their respectively associated arms 1, but it is only when lugs 15 are in juxtaposition to the ends of their respective arms 1 that they can engage the latter. At such times one of the slots 16 is in position to clear finger 17, the object of which will be explained. The several disks are arranged with their lugs 15 in different angular positions around the shaft as is clearly shown in Fig. 3, and as a result only one pair of lugs at a time can be in operable relation to a pair of arms 1. At each rotary step of shaft 6 a different pair of lugs are brought into operable relation with their respectively associated pairs of arms 1.

\Vhen a trunk bar is rotated into its preselected position it is retained there by means of a. latch member 23 which engages lugs 26 of arms 1. Each latch member 23 is pivotally mounted. on a pin. 2% and is provided with a spring 25 which tends to hold it in normal position. Finger l7 integral with latch member 23 is adapted to operate the latter to release the trunk bar. Finger 17 is engaged by its associated disk 14 upon longitudinal movement of shaft 6 in all positions of the disk except those in which the finger is cleared by one of the slots 16 as illus trated in Fig. 3.

Immediately after each setting up of a trunk bar, into its preselected position shaft 6 together with disks 14 rotates until the next succeeding idle trunk bar is located. Each longitudinal operation of shaft 6 results in the engagement with a disk 14% of the finger 17 associated with the previously preselected trunk bar. Latch member 28 is rotated by its finger 17 upon such engagement and releases the trunk bar permitting its return to normal.

Each longitudinal operation of shaft 6 results in simultaneously releasing one trunk bar and preselecting another.

Commutator 20 comprises a plurality of stationary terminals 21 each of which is associated with one of the trunks leading into the switch. Brush 22 fixedly mounted on a shaft 6 successively engages terminals 21 upon rotation of the shaft. The circuit of motor magnet 13 is extended through brush 22. When brush 22 engages a terminal 21 which is associated with a busy trunk the circuit through motor magnet 13 is closed and the latter operates to step shaft 6 around. Each succeeding step of shaft 6 moves brush 22 to the next succeeding terminal 21. So long as brush 22 continues to ll'ltllii, contact with terminals 21 which are associated with busy trunks motor magnet 13 will continue its operation, but as soon as the brush iinds a terminal which is associa ted with an idle trunk, the circuit through motor magnet 13 will be broken and its op eration will cease. lVhen brush 22 has come to rest on a terminal associated with an idle trunk a pair oflugs 15 associated with that trunk will bepositioned in operable relation to their associated arms The operating mechanism will continue at a standstill until the previously preselected trunk bar is en gaged in response to a call whereupon elec tro-magnet 18 will become energized and pull up its armature 19 imparting a longitudinal movement to shaft 6 thus releasing the engaged trunk bar and rotating the newly selected trunk bar into its preselected position to await the next succeeding call.

lVhat is claimed is:

1. A switch comprising a plurality of rotatable bars, contacts theretior, locks for said bars. and a common member control-- ling said locks.

2. In a switching mechanism. a plurality of rotatable trunk bars; means for rotating said trunk bars individually from normal non-contacting positions into contacting positions, means for locking said trunk bars in said contacting positions and releasing means for said trunk bars, said moving means and said releasing means being common and operable simultaneously.

3. In a switching mechanism, a plurality of rotatable and parallel trunk bars, mechanism for operating said bars individually from normal into preselected position, said mechanism including a rotatable and axially movable member, means operated by said member for locking said bars in operated position, and means for releasing said bars, a rotary and axial movement of said member being effective to cause the preselection or release of any one of said bars.

4:. In a switching mechanism, a plurality of operable trunk bars, a selective mechanism common to said bars, said mechanism including a rotatable and axially movable member, means carried by said member for selectively operating said bars, means for locking said bars in contacting osition, and means carried by said member or operating the second mentioned means. 7

5. In a switchng mechanism, a plurality of rotatable trunk bars, an operable device therefor comprising a shaft, means carried by said shaft adapted to be moved selective 1y into operable relation with said bars for releasing said bars, means to impart a longitudinal movement to said shaft for rotating and releasing said bars, and means for retaining said bars into contacting position.

6. In a line switch, a plurality of trunk bars, selective means for moving said trunk bars individually from normal to preselected positions, said selective means comprising a plurality of disks, one for each trunk bar, each of said disks adapted to engage its trunk bar only when situated in a definite angu lar position, locking means for retaining said trunk bars in their preselected positions, means operative by said disks for releasing said locking means to permit said trunk bars to return to normal, means for rotating said disks simultaneously, and means for moving said disks in operable relation with said trunk bars simultaneously.

7. In a line switch a plurality of trunk bars, selective means for moving said trunk bars individually from normal to preselected positions, said selective means comprising a shaft, a plurality of disks on said shaft, each of said disks being associated with one of said trunk bars and each adapted to engage its trunk bar only when situated in a definite angular position, locking means for retaining said trunk bars in their preselected positions, means cooperative with said disks 7 for releasing said locking means to permit said trunk bars to return to normal, means for rotating said disks, and means for moving said disks in a direction longitudinal of said shaft. 1

8, In a line switch a plurality of parallel trunk bars, an operating arm for each trunk bar, a shaft for operating said trunk bars, means forrotating said shaft, means for moving said shaft'longitudina'lly, a plurality of disks on said shaft, one for each operating arm, a lug on each disk adapted to engage said operating arm to rotate the trunk bar associated therewith upon longitudinal movement of said shaft and disks in one direction,said lugs situated in different angular positions relative to one another around said shaft, a locking device for each operating arm adapted to engage the latter when moved into its preselected position, and releasing means for said locking device,

said releasing means being operable by said disks upon a longitudinal movement thereof. 9. In a line switch a pluralityof parallel trunk bars, an operating arm for each trunk bar attached thereto and projecting laterally therefrom, a shaft normal to said trunk bars, step-by-step means for rotating said shaft, means for moving said shaft longitudinally, a plurality of disks, one for each operating arm mounted on said shaft, said disks rotatable and movable longitudinally with said shaft, a lug on the periphery of each disk forengaging one of said operating arms, said lugs situated in different angular positionaround said shaft, being so arranged that for each'successive rotary step of said shaft a different operating'arm will be in operative relation to its respective lug, a plurality of latches, one for each operating arm, each adapted to engage its operating armupon movement of the latter into its preselected position, and releasing means for 7 each of said latches, said releasing means operable by its associated disk upon longitudinal movement of said shaft.

In witness whereof, I hereunto subscribe my name this 7th day of October, A. D., a

ARTHUR C. MAGRATH. 

